Ummmm, you might claim to be some sort of production insider, but in the production notes of Batman Begins, Chris Nolan (Director), Lindy Hemming (Designer) Julian Murray (Sculptor) and Christian Bale (Bruce Wayne/ Batman) all disagree with you. You shouldn't disagree with the people who actually design/make/wear the suit, especially when the information is available to anyone who can google "Batman Begins".

Tinting is done before the foam is thrown in the oven. Too dense and it can come out black, but the actor can't turn their head (B'89- B&R), too thin and the material wrinkles and crumbles, because too much dye undermines the structural integrity of the foam.

Your "friends" Panther suit may still be in reasonable condition, but that was still a very thick suit in comparison, hence why it could be darker and glossier.

EDIT- This information is even on the Batman Begins Wikipedia page.

Batman wikipedia.. hmmm...

You're talking about one suit... one situation... perhaps it is Mr. Bale that had a problem with the "Begins" suit...
First off Llama.. I've made no claims... but I will tell you this... I've dealt with all of the materials in question, and all of the situations in question, when it comes to making these things. That said, this is not an argument.

This is me talking about what I know... and you talking about what you read...

Yes... tinting is done before it is in the oven... it is done before the foam is injected in to the mould.. like I mentioned in a previous post. It is done while the components are being added in to the bowl and while the foam is being mixed. ( usually in a Hobart mixer ).
Too much tint can effect the foam... but Black is easily achieved. Unless, of course , the foam technician adds to much of it...

Can foam crumble because of the tint?... yes... but you have to add a ****-load for it to get to that point. Usually the "crumble" has more to do with excessive curing agent, or over-baked foam in the oven. Sometimes the chemicals themselves can be bad or expired.

The density of the foam is not based on the colour, unless you are talking about the opacity of the colour itself?
The "density" , or firmness of the foam... is based on the technicians approach to the mix. During the "whipping" stage of the foam.. high-speed for a long time will add more air in to the mix. Thus, the foam's end result will be softer... and lighter...
It the technician goes through the "whipping" stage at a low speed?... for a short duration?... less air in the mix... less fluff... the foam does not rise as much, and will weigh more and feel more dense.
A lot of times the dense foam will be wanted or desired because it can take a hit better, and at times... last longer. But then you get a dense suit that will be tougher in a fight, but weigh a lot more and will feel hotter as well.

Some times, you may hear the terms "hero" suit.. or "stunt" suit?.. The hero being cleaner and lighter, the stunt suit being heavier and denser.. Both hero and stunt suits are made with the same material and colour... the "mix" will create a different result.

In the end.. the "density" is not judged or determined by the colour. That is why you can make really dense foam latex with no colour at all. the colour black has little to do with the fact that the actor can not turn his head. If the foam is too dense, and red... and the cowl is still too thick... the actor still won't be able to turn his head... you will get the same result no matter what colour it is.

My friend has a "Panther" suit because he was there when they were being made. And the "Panther" suit is actually thinner and lighter than the "Begins" suit. The neck of the cowl as well. The shine of these suits is more about the surface of the mould. If the piece being moulded has a high gloss to it, so will the pats that come out of it. Some of these suit have been filmed with out being painted, and some ended up being painted. The "gloss" is not about the pigment in the foam, or the colour chosen... the mould needs to have a clean and glossy surface. And the silicone needs to take the heat of the oven as well...

Again... I like the idea that you do research.. and are a fan of what has been done. That's cool...
Let's just say that the "internet" info... even on the official sights.. comes from the people in charge, not necessarily the people that did the work...

Sorry to the people that are reading this and thinking WTF.. like I said, I like this stuff... I'm hear to read and share what I and others think about the suits.
I'll calm down on the tech...
I just want to defend it because it works, and some actors and/or directors "hear" or "say" things about it.. and it becomes the truth rather than an opinion. Which is exactly what I'm sharing.. just my opinion...

Llama.. if you ever want to try this stuff... or make a suit?... let me know. Sometimes it's ok to ask people that know how to do it , rather than just reading up on the subject. Does the idea of a fabricating a suit interest you?
P.M. me... the more people involved, the cheaper it is to do...
cheers all...